Heat exchangers, in particular so-called oil-water heat exchangers on internal combustion engines are subjected to significant oscillations and vibrations, which is the reason why a connection plate via which the heat exchanger is mounted, for example, to an internal combustion engine, is formed comparatively thick and thus strengthened. However, a connection plate strengthened in this manner results in a comparatively high weight and requires in addition a certain installation space which can be a problem in particular with respect to a steadily decreasing installation space available within modern engine compartments.